The wrist joint, also known as the radio-carpal joint, is a synovial joint located at the junction between the forearm and hand. It allows for a variety of movements including flexion, extension, abduction, and adduction, and is classified as a condyloid joint.
Articular Surfaces
The articulating surfaces of the wrist joint include the inferior surface of the lower end of the radius, which comes into contact with the carpal bones (scaphoid and lunate). The ulnar bone does not form the proximal surface of the wrist joint, but is instead covered by the articular disk of the inferior radio-ulnar joint.
Joint Capsule and Synovial Membrane
The joint capsule of the wrist joint is located above the lower end of the radius and ulna, and below the proximal row of carpal bones. It is lined with a synovial membrane, which secretes synovial fluid to lubricate the joint. The wrist joint is stabilized by several ligaments, including the anterior, posterior, medial, and lateral ligaments.
Blood Supply and Nerve Supply
The blood supply to the wrist joint comes from the anterior and posterior carpel arches, and the nerve supply is provided by the anterior interosseous and deep branch of the radial nerves.
Movements
The wrist joint allows for a range of movements, including flexion and extension, which are performed by the long muscles crossing the wrist anteriorly. Abduction is performed by the flexor carpi radialis, extensor carpi radialis longus and brevis, long abductors, and short extensor of the thumb. Adduction is performed by the flexor carpi ulnaris and extensor carpi ulnaris.
Components of the Wrist Joint
In addition to the wrist joint, there are several other components that contribute to the overall function of the wrist. These include:
- The inferior radio-ulnar joint, a synovial pivot joint
- The intercarpal joint, a synovial plane joint
- The carpometacarpal joint, a synovial saddle joint
- The metacarpophalangeal joint, a synovial condylar joint
- The interphalangeal joint, a synovial hinge joint
Together, these joints work to allow for precise and flexible movement of the hand and fingers.
The wrist joint is an important component of the upper limb, allowing for a range of movements and contributing to the overall function of the hand and fingers. Understanding its structure and function is crucial for professionals in the fields of medicine and rehabilitation.
Quiz:
Wrist Joint Anatomy
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